High explosive munitions are an essential part of the arsenals of armed forces. Logistic operations of the armed forces frequently involve the transportation of high explosive munitions from manufacturing plants to ammunition storage depots, Ammunition Supply Points (ASP) and magazines, throughout the world. For military sites located within a national boundary, ground transportation is preferred and commonly conducted by rail or trucking freight. For military sites located overseas, the transportation of munitions includes ships and airplanes.
Explosive loaded munitions are transported and stored in manners intended to minimize risks of accidental detonation. However, accidents such as an overturned tractor trailer, a train derailment, or a cargo plane crash can occur during transport of the munitions. In some instances, the ensuing fire and heat resulting from the accident could provide sufficient thermal stimuli to cause the munitions to detonate. In such an event, a chain explosion could result from sometimes a single munition explosion. To minimize such a risk of accidental explosions, the United States Department of Defense requires that all munitions and weapons withstand unplanned stimuli such as heat from fire, shock from blast, and impact from fragments and bullets. This requirement is termed Insensitive Munitions (IM).
To meet the Insensitive Munition requirement, munitions must pass Fast Cook-Off (FCO) and Slow Cook-Off (SCO) test requirements, as established by MIL-STD-2105B, “Military Standard for Hazard Assessment Tests for Non-Nuclear Munitions”. In a typical Fast Cook-Off test, the munition is engulfed in the flames of a jet fuel (or gasolene) fire exhibiting a minimum average temperature of 1,600° F., to assess its response to rapid heating. In the Slow Cook-Off test, the munition is heated in a closed chamber at a linear rate of 6° F. (or 50° F.) per hour until a reaction occurs, to assess its response to gradual heating. The FCO and SCO tests are considered to be passed if the munition exhibits a Type V response where the test items only burn or scatter parts less 50 feet away from the burn pan or test oven.